We needed an MCP server that misbehaves on our command to test our own MCP gateway at work, but could only find well-behaved MCPs. That’s why we built a misbehaving MCP server ourselves and now share it on here, might be helpful for others building MCP gateways.<p>It’s similar to the MCP Inspector, but lets you test your client not your server.<p>We called it MCP Test Kitchen and it’s a (also hosted) MCP server that lets you:<p>* Connect any client that takes a URL and an Authorization header (Cursor, Claude Desktop or your own). It answers both 2025-11-25 and 2026-07-28 clients and logs which protocol revision each request declared.<p>* Pick one of 6 scenarios: HTTP transport errors, JSON-RPC error responses, tool results flagged isError, elicitation, multi round-trip requests (MRTR) via a C# SDK v2 scenario, and a baseline with a configurable delay. JSON-RPC and tool errors can be set to fail on a specific call, so the first call succeeds and the second fails. Resources and prompts are always on, each with a deliberately broken variant. If you want other scenarios, let us know.<p>* Watch every request in a live log with timing, method, caller, status and protocol version.<p>* Clo

We needed an MCP server that misbehaves on our command to test our own MCP gateway at work, but could only find well-behaved MCPs. That’s why we built a misbehaving MCP server ourselves and now share it on here, might be helpful for others building MCP gateways.<p>It’s similar to the MCP Inspector, but lets you test your client not your server.<p>We called it MCP Test Kitchen and it’s a (also hosted) MCP server that lets you:<p>* Connect any client that takes a URL and an Authorization header (Cursor, Claude Desktop or your own). It answers both 2025-11-25 and 2026-07-28 clients and logs which protocol revision each request declared. * Pick one of 6 scenarios: HTTP transport errors, JSON-RPC error responses, tool results flagged isError, elicitation, multi round-trip requests (MRTR) via a C# SDK v2 scenario, and a baseline with a configurable delay. JSON-RPC and tool errors can be set to fail on a specific call, so the first call succeeds and the second fails. Resources and prompts are always on, each with a deliberately broken variant. If you want other scenarios, let us know. * Watch every request in a live log with timing, method, caller, status and protocol version. * Clone a T